Method and apparatus for regulating high voltage in electrostatic generators



Dec. 17, 1968 B. J. FARMER 3,417,318

METHOD AND APPARATUS FOR REGULATING HIGH VOLTAGE IN ELECTROSTATIC GENERATORS Filed Jan. 28, 1965 fi i 4 is a 4" l4 POWER 6 SUPPLY l BOBBY J. FARMER INVENTOR ATTORNEY United States Patent Tex., assignor to Ling- Tex., a corporation of ABSTRACT OF THE DISCLOSURE This invention relates to a technique for regulating the voltage of Van de Graatf generators and the like by enclosing the high voltage electrode in an atmosphere of insulating gas, irradiating the gas with ionizing radiation, and controlling the intensity of the ionizing radiation.

This invention relates to methods and' apparatus for regulating high voltage and is particularly directed to methods and apparatus for controlling the voltage of high voltage generators, such as Van de Graaff generators and the like.

Many modern scientific techniques, such as nuclear particle acceleration, require the use of extremely high electrical potentials, often as high as several million volts. Numerous devices have been developed for generating such voltages. However, control and stabilization of such voltages has been a serious problem and no entirely satisfactory solution to this problem has been found heretofore. High voltage triodes have been useful for potentials below about 100,000 volts, but are of little value for higher voltages. Corona discharge systems can be employed for voltages of substantially any magnitude, but usually do not provide for adjustability and often induce arcing, especially for negative potentials. Moreover, where adjustability is required in corona discharge systems, the mechanism for accomplishing this is often extremely complicated and expensive and requires considerable maintenance. Other systems have suggested controlling the high voltage by regulating the supply voltage to the generator. Thus, in high voltage transformers or voltage doubling circuits, control of the high voltage is attempted by varying the input current, while in Van de Graaff generators, the belt charging supply is regulate'd. Unfortunately, the apparatus for such regulation is often complex and expensive and, since this method of regulating thehigh voltage is indirect, the response is usually slow and is conducive to over-correction or "huntmg.

These disadvantages of the prior art are overcome with the present invention and novel methods and apparatus are provided for regulating high voltage generators in a manner which is direct and rapid and is accomplished with apparatus which is simple and requires virtually no maintenance.

The advantages of the present invention are preferably attained by establishing an atmosphere of insulating gas about the generator or the high voltage electrode thereof, positioning a source of ionizing radiation in a location for exposing said gas to said radiation in a region between the high voltage electrode and ground, and controlling the intensity of said radiation incident on said gas. Ionization of the gas releases positive and negative ions which move in the electrostatic field between the high voltage electrode and ground. This constitutes an electric current which reduces the voltage of the high voltage electrode. Controlling the intensity of the radiation incident on the gas serves to regulate the rate of ionization and the current flow and, hence, serves to regulate the potential of the high voltage electrode.

Accordingly, it is an object of the present invention to provide improved methods and apparatus for regulating high voltage.

Another object of the present invention is to provide methods and apparatus for regulating high voltage which are effective for controlling voltages of substantially any magnitude.

An additional object of the present invention is to provide methods and apparatus for regulating high voltage which operate directly and rapidly, yet are simple in construction, economical to install, and require virtually no maintenance.

A specific object of the present invention is to provide apparatus for regulating a high voltage generator, said apparatus comprising means maintaining an atmosphere of insulating gas surrounding the high voltage electrode of said generator, a source of ionizing radiation positioned to expose said gas to said radiation, and means for controlling the intensity of said radiation incident on said gas.

Another specific object of the present invention is to provide a method for regulating a high voltage generator, said method comprising the steps of surrounding the high voltage electrode of said generator with an atmosphere of insulating gas, positioning a source of ionizing radiation to expose said gas to said radiation, and controlling the intensity of said radiation incident on said gas.

These and other objects and features of the present invention will be apparent from the following detailed description taken with reference to the figure of the accompanying drawing.

In the drawing:

The figure is a side view, partly in section,- of a portion of a high voltage generator embodying the present invention.

In the form of the present invention chosen for purposes of illustration in the drawing, the figure shows a high voltage electrode 2 which receives charging current through high voltage conductor 4 from any suitable source, not shown. A gas chamber 6 surrounds the electrode 2 and is connected to ground, as shown at 8, while a suitable insulator 10 encircles the high voltage conductor 4 and serves to insulate the chamber 6 from the high voltage. An atmosphere of insulating gas, such as compressed air, hydrogen, fluorine, or the like, is contained within the chamber 6 and serves, normally, to insulate the chamber 6 from the high voltage electrode 2. To stabilize and control the high voltage of electrode 2, a source of ionizing radiation, such as ultraviolet lamp 12, is mounted in a position to expose the gas to the radiation from the source 12. The lamp 12 may be energized by a suitable power supply 14, and appropriate current control means, such as'potentiometer 16, are connected in series with the lamp 12 and energizing means 14 to control the intensity of the radiation emitted by the lamp 12. Finally, a Faraday cage 18 or the like is inter posed between the high voltage electrode 2 and the radiation source 12 to prevent arcing.

. In operation, electrical current is supplied through conductor 4 to raise the potential of high voltage elec trode 2 to a desired magnitude and the gas contained within chamber 6 aids in establishing and maintaining the potential of electrodes 2 by insulating the electrode 2 from the groundedchamber 6. To regulate the potential of the electrode 2, the source 12 is energided to expose the gas to ionizing radiation to cause ionization of the gas. When the gas is ionized, the resulting positive and negative ions will migrate in the electrostatic field which exists between high voltage electrode 2 and the grounded chamber 6, thereby establishing an electric current be tween the electrode 2 and the chamber 6. The intensity of theionizing radiation emitted by source 12 can be controlled by varying the setting of potentiometer 16 and it is found that increasing the intensity of the ionizing radiation incident on the gas will increase the ionization of the gas and will increase the magnitude of the current between electrode 2 and chamber 6. This serves to reduce the potential of electrode 2. Conversely, reducing the intensity of the ionizing radiation incident on the gas Will reduce the ionization of the gas and will reduce the magnitude of the current between electrode 2 and chamber 6. This permits the potential of electrode 2 to be increased. Thus, the potential of the high voltage electrode 2 may be controlled by varying the intensity of the ionizing radiation emitted by the source 12.

Numerous other variations and modifications may also be made without departing from the present invention. Accordingly, it should be clearly understood that the form of the inventiondes'cribed above and shown in the figure of the accompanying drawing is illustrative only and is not'intended to limit the scope of the invention.

What is claimed is: 1. Apparatus for regulating a high, voltage generator, said apparatuscomprising:

a high voltage electrode forming a part of said generator, means maintaining an atmosphere of insulating gas about the high voltage electrode of said generator, means for exposing said gas to ionizing radiation,

electrical shielding means transparent to said raidation interposedbetween said high voltage electrode said means for exposing said gas to ionizing radiation, and g means for controlling the intensity of said radiation incident-on said gas. 2. Apparatus for regulating a high voltage generator, said apparatus comprising:

a high voltage electrode forminga. part of said generator, 1 means maintaining an atmosphere of insulating ga about the high voltage electrode of said generator, a source of ionizing radiation positioned to expose said gas to said radiation, a Faraday cage interposed between said high voltage electrode and said source, and means for controlling the intensity of said radiation incident on said gas. 7 3. Apparatus for regulating a high voltage generator,

' said apparatus comprising:

a high voltage electrode forming a part of said generator, means'm-aintaining an atmosphere of insulating gas about the high voltage electrode of said generator, a source of ionizing radiation positioned to expose said gas to said radiation, a' Faraday cageinterposed between said high voltage electrode and said source, and

means for controlling the intensity of said radiation emitted by said source.

4. Apparatus for regulating a high voltage generator,

said apparatus comprising:

a high voltage electrode forming a part of said generator,

a gas-tight chamber connected to ground and enclosing at least the high voltage electrode of said generator,

a quantity of insulating gas contained Within said chamber and insulating said chamber form the potential of said electrode,

means for exposing said g-asto ionizing radiation,

a Faraday cage interposed between said electrode and said means for exposing said gas to ionizing radiation, and 7 means for controlling the intensity of said radiation incident on said gas. I

5. Apparatus for regulating a high voltage generator,

said appaartus comprising: a

a high voltage electrode forming a part of said generator,

a gas-tight chamber connected to ground and enclosing at least the high voltage electrode of said generator,

a quantity of insulating gascontained within said chamber and insulating said chamber from the potential of said electrode,

a source of ionizing radiation positioned said gas to said radiation,

a Faraday cage interposed between said'electrode and said source, and

means for controlling the intensity of said radiation emitted by said source.

6. Apparatus for regulating a high voltage generator,

said apparatus comprising:

a high voltage electrode forming a part of said generator,

a gas-tight chamber connected to ground and enclosing at least the high voltage electrode of said generator,

a quantity of insulating gas contained within said chamber and insulating said chamber from themtential of said electrode,

a source of ionizing radiation position within said chamber 'to expose said gas to said radiation, and

a Faraday cage interposed between said electrode and said source, and

means for controlling the intensity of said radiation incident on said gas.

to expose 7. Apparatus for regulating a high voltage generator,

said apparatus comprising:

a high voltage electrode forming a part of said generator,

a gas-tight chamber connected to ground and enclosing at least the high voltage electrode of said generator,

a quantity of insulating gas contained Within said chamber and insulating said chamber from the potential of said electrode,

an ultra-violet light source positioned within said chamber to expose said gas to said light, and means for controlling the intensity of said light emitted by said source.

8. A method of regulating a high voltage generator having a high voltage electrode, said method comprising the steps of:

enclosing said highvoltage electrode in an atmosphere of insulating gas,

irradiating said gas with ionizing radiation from a suitable source, and r controlling the intensity of said radiation incident on said gas.

9. A method of regulating a high voltage generator having a high voltage electrode, said method comprising the steps of:

enclosing said high voltage electrode in an atmosphere of insulating gas,

irradiating said gas with ionizing radiation from a suitable source, and

controlling the intensity of said radiation emitted by said source.

References Cited UNITED STATES PATENTS 2,049,099 7/1936 Axelos et a1. 313-182 X 2,548,452 4/1951 Turner 3222 2,588,081 3/1952 Bousman 322-2X 10 I. D. MILLER, Primary Examiner.

WARREN E. RAY, Assistant Examiner.

US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,417,318 December 17, 1968 Bobby J. Farmer It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 49, after "electrode" insert and Signed and sealed this 24th day of March 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR. 

